Exhaust gas duct cooled with water

ABSTRACT

The invention concerns an exhaust gas duct with an exhaust gas guide channel ( 13 ) which is placed, leaving an air-filled space ( 18 ), in a sheath wherein circulates a cooling liquid and enclosing at least partially said exhaust gas guide channel ( 13 ). The invention is characterised in that said sheath is divided along the row of cylinders and has a base body ( 10   b ) wherein the exhaust gas guide channel ( 13 ) can be inserted, and a cover ( 3 ) closing said base body, thereby obtaining a modular structure for transporting exhaust gas which enables continuous control, in particular, control over the exhaust gas guide channel.

TECHNICAL FIELD

This invention relates to an exhaust line for a cylinder bank of aninternal combustion engine, an exhaust conveying duct being enclosed,beyond an air gap, by a housing at least partly surrounding the exhaustconveying duct, through which housing there is a flow of coolant.

BACKGROUND ART

Such an exhaust line is shown in German patent documents DE 42 06 247issued Jun. 3, 1993 on an exhaust gas line for a row of cylinders of aninternal combustion engine. This exhaust line has an extrusion-moldedpart made of light metal into which there are recessed severallongitudinal chambers, mutually connected at least in the closurecovers, for cooling water. This extrusion-molded part is approximatelyround in shape and has openings that are arranged in the region of theindividual exhaust ports of the respective cylinder heads. Inserted intothe extrusion-molded part is a one-piece gas conveying duct, which mustbe connected to the previously mentioned openings in gas-tight fashion,in a manner not described. Precise making of a connection is verycostly. Inspection of the gas conveying duct after assembly is scarcelypossible.

It is an object of the invention to furnish an exhaust line of easilymaintainable construction for a cylinder bank of an internal combustionengine.

OBJECTS AND SUMMARY OF THE INVENTION

This object is achieved by virtue of the fact that the housing is splitalong the cylinder bank and has a housing base, into which the exhaustconveying duct is insertable, and a housing cover covering the housingbase. A modular exhaust line construction is thereby created, whichpermits, for example, inspection of, in particular, the exhaustconveying duct at any time, without great effort, by removing thehousing cover. In this way the air gap can be inspected over the entirelength of the removed housing cover and examined, for example, for leaksof any kind that may be present.

In development of the invention, the housing base is divided intohousing base segments, preferably U-shaped and enclosing a certainnumber of cylinders. These can be, for example, two cylinders each, sothat identical housing base segments can be mounted for various internalcombustion engines if, for example, the internal combustion engine ismade as an eight- or 16-cylinder internal combustion engine of V design.Naturally, it is also contemplated in the context of the invention toprovide additional housing base segments for, for example, threecylinders, so that other cylinder numbers are also feasible. In additionto these housing base segments, which are assigned to the individualcylinders, there are also various housing base end segments, which canbe made, for example, as covers and/or connecting devices for a(liquid-cooled) turbocharger, with the incorporation of wastegate ductsif appropriate.

In corresponding development of the invention, the housing cover islikewise divided into housing cover segments enclosing a number ofcylinders. What was said about the housing base segments applies asappropriate to these housing cover segments.

In development of the invention, the housing base segments areattachable to the cylinder heads and have openings in the region of theexhaust port of each cylinder head. In further development, the exhaustconveying duct is attachable to the individual cylinder heads ingas-tight fashion with flange regions extending into the openings. Thus,according to this design, the housing base segments are first mountedand then the exhaust conveying duct is inserted into these U-shapedhousing base segments. Finally, the housing cover segments are thenmounted. In particular, moreover, individual mounting or in particularremoval, for example for the repairing of a cylinder, can take place byvirtue of the fact that, in development of the invention, the exhaustconveying duct is formed by separate pipe segments assigned to eachcylinder. Naturally, it is a prerequisite here that the cylinders or inparticular the cylinder heads be removable individually or incorrespondence to the segments of the housing base segments.

In development of the invention, the housing base segments have throughcoolant conveying ducts in the region of the two parallel arms of theU-shaped housing. Coolant, in particular cooling water, flows throughthese coolant conveying ducts in common. The coolant flows in onedirection along the cylinder bank in both coolant conveying ducts.Accordingly, the housing base end segments are designed so that externalor internal coolant ports are connectable to them and these coolantports distribute the coolant into the coolant conveying ducts. Thesecoolant conveying ducts are included in the coolant conveyance from theinternal combustion engine discharge via the turbo charger to a platehead exchanger.

In further development of the invention, a coolant duct is also recessedin the housing cover. This coolant duct connects, along one cylinderbank A, a thermostat housing to an intercooler and, along the othercylinder bank B, the intercooler to the plate heat exchanger. Theseconnections were formerly effected via separate pipes to be attachedexternally to the internal combustion engine. Integration of these linesinto the housing cover results in, on the one hand, additional coolingof the exhaust pipe and, on the other, the saving of the formerlyrequired pipes. Naturally, the corresponding ports, pipe clamps and hoseconnections are likewise saved.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantageous developments of the invention are presented in thedescription of the drawings, in which an exemplary embodiment of theinvention, illustrated in the figures, is described in greater detail.

FIG. 1 shows an overall schematic diagram with the housing base andhousing cover according to the invention.

FIG. 2 shows a detail view of the housing base, the exhaust pipe and thehousing cover.

DETAILED DESCRIPTION OF THE INVENTION

The overall schematic diagram of FIG. 1 shows the coolant system of amulti-cylinder V-type diesel internal combustion engine, which can beused, for example, for ship propulsion. In this case, there is a plateheat exchanger 1, which raw water enters via an inlet 1 a and againexits via a discharge 1 b. Correspondingly, the coolant flows incountercurrent into the plate heat exchanger via an inlet 1 c and outagain via a discharge 1 d. From the discharge 1 d, the coolant isconveyed via a coolant duct 2 (FIG. 2) in housing cover segments 3, 3 aof a cylinder bank to an intercooler 4. From intercooler 4, the coolantpasses along the opposite cylinder bank of the internal combustionengine, back into a housing cover segment 3 a, and then into a housingcover segment 3. From there the coolant is delivered to a coolant pump5, which has a suction chamber and two pressure chambers. From one ofthe pressure chambers, the coolant is delivered via an oil cooler 6 intothe coolant system (coolant header 8 b) of internal combustion engine 7,while the second pressure chamber delivers the coolant directly into afurther coolant system (coolant header 8 a). After flowing through theinternal combustion engine, the coolant passes from coolant headers 8 a,8 b into respective turbochargers 9 a, 9 b, to pass from there viahousing base segments 10 a, 10 b and housing base end segments 10 c backon the opposite side of the internal combustion engine into thermostathousing 11 a, 11 b. A sidestream is also conveyed from coolant headers 8a, 8 b, via diaphragms 22 a, 22 b, to thermostat housings 11 a, 11 b.According to the setting of high-temperature thermostats in thermostathousings 11 a, 11 b, the main stream is conveyed either to plate heatexchanger 1 or to low-temperature thermostats 12 a, 12 b. Theselow-temperature thermostats 12 a, 12 b convey the coolant either tocoolant pump 5 or to the connection between discharge 1 d and housingcover segment 3. Housing base segments 10 a, 10 b, 10 c and housingcover segments 3, 3 a are integrated into the single-circuit mixedcooling system and serve primarily as coolant lines replacing the formerexternal pipes.

FIG. 2 shows a detail view of the housing base, the exhaust pipe and thehousing cover. The housing base is cut in the region of a housing basesegment 10 b, which in turn is covered by a housing cover segment 3. Theexhaust conveying duct with individual pipe segments 13, each assignedto one cylinder, is inserted into housing base segment 10. Assembly isdone by first bolting housing base segment 10 b to a cylinder head 14,which is sketchily illustrated. Next, pipe segments 13 are inserted intothese housing base segments 10 b and likewise bolted to cylinder head14, each with a flange region 15 that extends through a correspondingopening 16 in housing base segment 10 b. Pipe stubs 17 make thegas-tight connection between the interior of pipe segments 13 andexhaust port 21 of each cylinder head 14. For the rest, these pipesegments 13 are designed as so-called pearl elements.

Pipe segments 13 are inserted in housing base segment 10 b so as to forman air gap 18. Housing base segment 10 b is U-shaped and has coolantconveying ducts 20 a, 20 b along the two parallel arms 19 a, 19 b of theU. In the region of the end regions of housing base segments 10 b,coolant conveying ducts 20 a, 20 b narrow to approximately circularcoolant conveying duct passages 20 c.

A coolant duct 2 is recessed into housing cover segment 3, filling thewhole interior along housing cover segment 3 and being constricted to anapproximately circular opening only in the region of the opposite endpieces. Housing cover segment 3 is attached to housing base segment 10 bwith bolts.

What is claimed is:
 1. An exhaust line for a cylinder bank of aninternal combustion engine having a cylinder head (14) covering eachcylinder of the cylinder bank and presenting an exhaust port (21) foreach cylinder, said exhaust line comprising: a housing including a firstU-shaped housing segment (10 b) having opposite ends, a base secured tosaid cylinder head (14) and a pair of spaced arms (19 a, 19 b) extendingfrom said base, said base having openings (16) aligned with said exhaustports (21); a second U-shaped housing segment (10 a) secured in alignedrelation to one of said ends of said first U-shaped housing segment (10b); a housing end segment (10 c) secured to the other of said ends ofsaid first U-shaped housing segment (10 b); a housing cover including afirst cover segment (3) releasably secured to said first U-shapedhousing segment (10 c) and a second cover segment (3 a) releasablysecured to said second U-shaped housing segment (10 a), coolantconveying ducts (20 a, 20 b) in said arms (19 a, 19 b) of said firstU-shaped housing segment (10 b); an internal cooling duct (2) in saidhousing cover and an exhaust conveying duct positioned within saidhousing to provide an air gap between said exhaust conveying duct andsaid housing, said exhaust conveying duct including flange regions (15)which extend through said openings (16), respectively, and are secureddirectly to the associated cylinder head (14) independent of saidU-shaped housing segments to form a gas tight connection of said flangeregions (15) with said exhaust ports (21).
 2. The exhaust line of claim1 including fluid flow connections permitting coolant flow through saidinternal coolant duct (2) in said housing cover (3, 3 a) independentlyof said coolant conveying ducts (20 a, 20 b).
 3. The exhaust line ofclaim 1 wherein coolant passing through said ducts (20 a, 20 b) in saidarms (19 a, 19 b) of said U-shaped housing segment also passes throughthe associated liquid cooled turbo charger.